Ship Rolling Control Based On Active Disturbance Rejection Control

With the development of global shipping industry,the safety and stability of ships have been paid more and more attention.Ships in navigation and operation will be subject to external winds,waves,currents and other marine environment.This will result in a variety of rocking movements.The ship's shaking will damage the hull structural components,reduce speed and stability,result in crew seasickness,and effect the efficiency of personnel on board.What's worse,it may lead to ship capsizing.Most shipwreck accidents are due to severe rolling movements.Therefore,the study of ship's rolling response to waves and seeking how to reduce rolling is of great theoretical and practical value to improve navigation stability and safety as well as the ship control design system.Meanwhile,it is also necessary for current ship technology to develop in the direction of automation.This paper based on the fin stabilizer,combines the nonlinear characteristics of the ship roll and uses the ADRC algorithm to achieve its end.It mainly includes the following aspects:(1)Based on the theory of spectrum analysis,it establishes the mathematic model for random waves of long peak wave and wave dip model.The simulation of different sea conditions is carried out.Then the ship nonlinear rolling and liner rolling mathematical model is established according to force analysis,then carried out the ship simulation under open-loop control.(2)We systematically analyzed the working principle and system composition of fin stabilizer in order to obtain the transfer function of various component systems.According to the ship data,we establish and simulate PID control system for fin stabilizer.We get the simulation curves under PID control.After a series of analysis,we summarize the advantages and disadvantages of PID control.(3)The principle and structure of ADRC are expatiated,and the ADRC system of fin stabilizer is established based on the extended state observer.Simulink simulation for different sea conditions is carried out with the help of MATLAB.The simulation curve under ADRC is obtained.Then analysis the anti-rolling effect of ADRC.(5)In the parameters optimized from the disturbance rejection control system,the artificial immune algorithm is introduced against the weakness of basic particle swarm optimization algorithm,and get immune particle swarm optimization algorithm.With the help of this algorithm,we can optimize and control parameters thus obtaining the best results.